centos7.9安全加固
1、限制用户登陆
vim /etc/hosts.deny，若禁止192.168.0.158对服务器进行ssh的登陆，添加如下内容
sshd : 192.168.0.158
添加完毕后就生效了，直接用192.168.0.158访问主机，就无法连接了，显示
Connection closing...Socket close.
Connection closed by foreign host.
Disconnected from remote host(192.168.0.x:22) at 09:46:24.